High Temperature Oxidation-Reduction Process to Form Porous Structures on a Medical Implant

Abstract

A system for treating abnormalities of the cardiovascular system includes a stent having a porous therapeutic agent carrying zone comprising oxidation and reduction products of one or more metals in the stent framework. Another embodiment of the invention includes a method of manufacturing a therapeutic agent carrying stent comprising exposing a metallic stent framework to oxidizing and reducting conditions, and forming a therapeutic agent carrying zone on the surface of the stent framework that includes oxidation and reduction products of one or more metals in the stent framework.

Description

TECHNICAL FIELD[0001]This invention relates generally to biomedical devices that are used for treating vascular conditions. More specifically, the invention relates to a therapeutic agent eluting stent having one or more therapeutic agent eluting structures.BACKGROUND OF THE INVENTION[0002]Stents are generally cylindrical-shaped devices that are radially expandable to hold open a segment of a vessel or other anatomical lumen after implantation into the body lumen.[0003]Various types of stents are in use, including expandable and self-expanding stents. Expandable stents generally are conveyed to the area to be treated on balloon catheters or other expandable devices. For insertion into the body, the stent is positioned in a compressed configuration on the delivery device. For example, the stent may be crimped onto a balloon that is folded or otherwise wrapped about the distal portion of a catheter body that is part of the delivery device. After the stent is positioned across the lesi...

AI Technical Summary

Benefits of technology

[0014]One aspect of the present invention provides a system for treating abnormalities of the cardiovascular system comprising a catheter and a therapeutic agent-carrying stent disposed on the catheter. The stent includes a metallic sten

Problems solved by technology

Soon after the procedure, however, a significant proportion of treated vessels restenose.

Stent insertion may cause undesirable reactions such as inflammation resulting from a foreign body reaction, infection, thrombosis, and proliferation of cell growth that occludes the blood vessel.

The coating is sometimes damaged during expansion of the stent at the delivery site, causing the coating to chip off the stent and release flakes of the polymer coating, which reduces the effective dose of the drug at the treatment site, and under some circumstances, may result in emboli in the microvasculature.

Although there is some control over the porosity, including the size and number of pores, the strength of the oxide zone suffers as porosity increases.

This is especially detrimental for an oxide coatings on the surface of a stent.

The expansion and contraction of the diameter of the stent often causes the oxide coating to buckle and break from the stent surface, limiting the practical applications of these coatings.

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